Multimonitor: (Minor issue) 1 of 3 displays doesn't get the background color

[ispanos]

I have 3 displays in a ┐ shape and as you can see in the screenshot, the top left display doesn't get the treatment.

I'm not annoyed by it, I'm only posting in case it is easy to fix or helps you find another bug.

[queenbiscuit311]

I've observed the same behavior here, but only sometimes.

Here's a screenshot from one attempt:

Here's one from another attempt without changing anything:

Seems to be random.

The window being there doesn't affect it, it just happened to be there when I saw it happen this time.